The present invention relates generally to an improved aquaculture system, and more particularly to an aquaculture system which is designed for raising of fish and/or other marine life, and more particularly to such a system which is designed for substantially continuous operation with a single tank means, and without requiring separate vessels for clarification and/or digestion. The system of the present invention utilizes a plurality of discrete foam substrate members which are recirculated through the vessel on a substantially continuous basis. Means are provided for removal of solid waste products from the vessel, as well as from the surface of the discrete foam substrate members.
Aquaculture is a rapidly expanding and widening industry. The growth of this industry is in response to increasing demands for protein, and including an increasing demand for fish and other marine animals as a source of either food or brood stock. In addition, aquaculture has expanded in response to concerns over quality of the harvest for use as food due to possible harmful effects of pollution of the lakes, seas and oceans, and also due to concerns of over-harvesting of available current resources. Aquaculture provides a relatively safe and continuous source of supply for fish and other marine life for either food or brood stock purposes.
Consumer demand for fish, seafood and the like is increasing rapidly. Because of concerns for over-harvesting of certain species of fish, new sources other than natural habitat such as lakes, seas and oceans must be found to satisfy the ever-increasing demand for the more desirable species. Aquaculture may be the means by which the supply of seafood may be appropriately increased or at least maintained and thus endeavor to meet the demand.
In the past, aquaculture systems have typically utilized a plurality of large vessels for raising fish to mature and suitable sizes. Typically, the systems include a vessel where the fish are housed, with additional vessels being utilized for treatment of the water, including additional vessels used for operations such as water clarification and waste digestion. These vessels are employed so as to reduce concerns related to over-consumption of water, as well as the creation of a possible source of pollution with the used water. The present invention provides improvements in aquaculture systems wherein a single vessel is employed and the water is being constantly treated so as to maintain its suitability for the purpose including the maintenance of properties, an appropriate oxygen content or concentration, as well as an appropriate and consistent level of purity and clarity. In the present arrangement and system, the fish are able to grow and mature, and are also able to do so within a healthy, sound, and tolerable environment.
The system of the present invention is of the closed/recirculating type. It has been found that closed/recirculating systems reduce the quantity of water employed, and accordingly reduce the release of any harmful effluent or waste products. These advantages are available over both single-pass aquaculture systems and pond culture systems. The production of closed/recirculating systems has been found to provide a higher quality as well as a more uniform quality of product, in addition to the reduction of water-borne contaminants. In the past, attempts have been made to produce fish and other marine animal life in closed/recirculating aquaculture systems. Normally, however, these have been undertaken as incremental enhancements of natural systems. Also, attempts have been made to improve the quality of pond cultures through oxygenation of the water, recirculation of the water, as well as purification of the water. Generally, however, these enhancements have added substantially to the cost of the system, and hence have also contributed to an increase in product production costs.